Automatic means for draining crude-oil tanks



T. s. McCAHON.

AUTOMATIC MEANS FOR DRAINING CRUDE OIL TANKS.

APPLICATION FILED APR. 26,19l9.

Patented Eel). 3,1920.

2 SHEETS-SHEET 1- vwewtoz Thom a5 aK-W T. s. McCAHON.

AUTOMATIC MEANS FOR DRAINING CRUDE OIL TANKS. APPLICATION FILED APR. 26, l9l9.

1,329,983. Patented Feb. 3,1920.

2 SHEETS-SHEET 2.

awn box UNITED STATES PATENT OFFICE.

THOMAS MCCAHON, OF CHICAGO, ILLINOIS.

AUTOMATIC MEANS FOR DRAINING CRUDE-OIL TANKS.

To all whom it may concern: 7

Be it known that I, THOMAS S. MoCAHoN, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Automatic Means for Draining Crude-Oil Tanks; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and fi ures of reference marked thereon, which form apart of this specification. 7

This invention relates to new and useful improvements in automatic drain apparatus for oil tanks, etc, and the object in view is to produce a draining system which will work automatically in draining crude oil or any combustible liquid from a burning tank, thereby salvaging the oil which otherwise would be a total loss.

More specifically, the present invention consists in the provision of thermostatically operated means for releasing a trap door in the bottom of a tank to permit the oil to make exit to any suitable location, and in the provision of anautomatically releasing fire gate to close the exit after the oil has drained from the tank and thereby smother and extinguish the flame.

My invention comprises further various details of construction, combination and arrangement of parts which will be hereinafter fully described, shown in the accom-f panying drawings and then specifically defined in the appended claims.

My invention is illustrated in the accompanying drawings which, withthe letters of reference marked thereon, form a part of this application, and in which;

Figure 1 is a vertical central sectional view showing the application of my invention to a tank. Fig, 2 is an enlarged detail sectional view in elevation, showing the trap door' in an open position.

Fig. 3 is a cross sectional view through the tank, showing the lower portion in plan view.

Fig. 4 is an enlarged detail view of a thermostatic element, and

Fig. 5 is a vertical sectional view through the upper portion of the tank, parts being shown in elevation, Fig. 6 is a detail sec- Specification of Letters Patent.

Patented Feb. 3, 1920.

Application filed April 26, 1919. Serial No. 292,923.

tional perspective view, and Fig. 7 is a detail perspective of a part of the invention.

Reference now being had to the details of the drawings by numerals:

1 designates an oil tank adapted to restore crude oil, and having in the bottom thereof a door frame 2 which is normally closed by a trap door 3. Said door is hinged at 4 to the surrounding frame, and 5 designates a calking interposed between the contact portions of the door and the frame in order to make a liquid tight joint. Secured to said door is a bracket or hanger 6, and 7 is a casting bolted, or otherwise fastened, to the door frame, and has pivotally mounted in slots 8 in upwardly extending lugs thereon a pin 9 which is fastened to a tilting lever 10 one end of which is adapted to engage the bracket member or hanger 8 in the manner shown in the drawings.

A gravity lever 11 is pivotally' mounted upon a pin 12 journaled in the walls of a slot of an upward projection of the casting 7 and the short end of said lever engages the adjacent endof the tilting lever 10 and serving to hold the same in the retaining position shown in Fig. 1 of" the drawings. A cable 13 is fastened to the long arm of the lever 11, passes over the pulley 14 and winds about a shaft 15 to which is fixed a ratchet wheel 16 mounted upon a bracket member 17 secured to the tank. A pivotal pawl 18 engages the ratchet. wheeland holds the same from rotation in one direction.

A thermostaticelement 19, detail of which is shown in Fig. 5 of the drawings, and made offa fusible metal, is adapted to receive' a loop 20 of the cable to hold the latter taut and the levers before referred to in locked relation with each other and with'said trap door. Said thermostatic element made of a fusible metal, will'melt at a comparatively low temperature and has reinforcing wires 21 of the shape shown in Fig. 5 embedded in the metal for the purpose of causing the element to withstand the extra pressure which would come upon the same incident to holding the welght of the oil which would come upon the trap site sides thereof. are drawn frictionally against the loop with sufficient force to grip and hold the same against any pressure that might otherwise tend to cause the cable to slip through the element.

A fire door 23 is hinged upon a bracket member 24 fastened to the door frame in the bottom of the tank, and a asket 25 is sealed ina rabbeted part of the door and which is adapted, when the latter is closed, to form a liquid tight joint intermediate the fire door and the frame '2, as shown in Fig. 2 of the drawings. A cable26 is fastened at one end to a steel eye 27 fastened to the face of the door 23 and its other end is secured to a fusible plug 28 secured to the bottom of the tank.

Said cable 26 is of such length as will normally hold the gate 23 at the inclination shown in Fig. 3 .of the drawings so that when the plug is forced the door will fall by gravity to a closed position.

Leading fromthe opening in the bottom of the tank is a drain passageway 80 with a trap 31 therein and through which the oil makes exit from the tank when the door in the bottom=thereofis opened and which serves as a means for conveying the oil to any place of safety. a

In operation, the parts in their normal positions are shown in Fig. l of the drawings, in which the trap door is closed and sealed, and in the event of the oil in the tank being ignited from any source and commencing toburn the heat, generated in the upper portion ofthe tank, will fuse the metal of the thermostatic element 19 and the Weight of the oil upon the trap door will cause the same to swing down to an open position, this movement of the door being permitted by the tilting of the levers 10 and 11 incident to slacking the cable 13. The oil from the tank is siphoned off from the drain passageway 30 with the fire still burning upon its upper surface. After the oil is drained from the tank and the heat, incident to burning of the oil, will fuse the plug 28 thus releasing the cable and the fire gate will close by gravity and smother the flame and prevent any further burning of the oil which has passed through the bottom of the tank.

It will be understood that the drain passageway normally contains water, as a precaution against any back fire from any out side source. Y

What I claim to be new is:

1. Automatic means for draining crude oil tanks, comprising in combination with a tank having an exit opening in the bottom leading to a drain pit, a trap door normally closing said opening, a tilting memberholding said door closed, a pivotal lever engaging-at one end said member, and a cable secured to its other end, means for holding the cable taut, a thermostatically fusible element adapted to frictionally hold a loop in saidcable, and which element when fused will cause the cable to slack and permitihe trap to be released and open by. the weight thereon, an automatic thermostatically operated firing door adapted to close the opening at the bottom of the tank when the oil drains therefrom. i

2. Automatic means for draining crude oil tanks, comprising in combination with a V tank having an exit opening in the bottom leading to a drain pit, a trap door normally closing said opening, artilting member holding said door closed, a pivotal lever engaging at one end said member, and a cable secured to its otherend, a shaft upon which said cable winds, a pawl and ratchet for holding the cable taut, said cable having a loop formed therein, and a fusible thermostatic element for holding the loop, and which element when fused will cause the cable to slack, the lever to tilt and the trap door to open under weight of the oil thereon to permit the tank to drain, and automatically operated means for closing the exit opening when the oil has run from the tank.

3. Automatic means for draining crude oil tanks, comprising in combination withla tank having an exit opening in the bottom leading to a drain pit, a trap door nor- 'mally closing said opening, a tilting n1ember holding said door closed, a pivotal lever engaging at one end said member, and a cable secured at its other end, a shaft upon which said cable winds, a pawl and ratchet for holding the cable taut, said cable having a loop formed therein, anda fusible thermostatic element for holding the'loop,

and which element when fused willcause signature.

- THOMAS S. MCCAHON. 

